Line of Credit Facility, Additional Borrowing Capacity

No definition available.

Name:	omcl_LineofCreditFacilityAdditionalBorrowingCapacity
Namespace Prefix:	omcl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Stock Repurchase Program, Authorized Annual Amount

+ References

No definition available.

+ Details

Name:	omcl_StockRepurchaseProgramAuthorizedAnnualAmount
Namespace Prefix:	omcl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=omcl_WellsFargoBankNationalAssociationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_EurodollarMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_FederalFundsEffectiveSwapRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=omcl_November2014StockRepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Credit Agreement - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Jan. 05, 2016	Nov. 05, 2014	Nov. 04, 2014	Sep. 30, 2013	Sep. 25, 2013
Line of Credit \| Letter of Credit \| Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Revolving credit facility with a letter of credit sub limit					$ 10,000,000
Increases in to aggregate commitments (does not exceed $25 million)					$ 25,000,000
Commitment fee percentage	0.25%
Line of Credit \| Revolving Credit Facility \| Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Revolving credit facility with a letter of credit sub limit						$ 75,000,000
Eurodollar \| Line of Credit \| Letter of Credit \| Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Amounts draw under the Credit Agreements bears interest rate	1.75%
Federal Funds Effective Swap Rate \| Line of Credit \| Letter of Credit \| Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Amounts draw under the Credit Agreements bears interest rate	0.50%
London Interbank Offered Rate (LIBOR) \| Line of Credit \| Letter of Credit \| Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Amounts draw under the Credit Agreements bears interest rate	1.75%
November 2014 Stock Repurchase Program
Debt Instrument [Line Items]
Authorized amount of repurchase of common stock			$ 50,000,000	$ 25,000,000
Subsequent Event \| Letter of Credit \| Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Revolving credit facility with a letter of credit sub limit		$ 10,000,000
Subsequent Event \| Line of Credit \| Revolving Credit Facility \| Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Revolving credit facility with a letter of credit sub limit		200,000,000
Subsequent Event \| Line of Credit \| Secured Credit Facility \| Wells Fargo Bank, National Association
Debt Instrument [Line Items]
Revolving credit facility with a letter of credit sub limit		$ 400,000,000